Added check for `netinet/in.h` header file availability

configure.ac

@@ -263,6 +263,7 @@ AC_SUBST(ASAN_ENV_FLAGS)
 dnl Checks for header files.
 AC_HEADER_STDC
 AC_CHECK_HEADERS(sys/param.h)
+AC_CHECK_HEADERS(netinet/in.h)
 
 dnl Checks for typedefs, structures, and compiler characteristics.
 AC_C_BIGENDIAN

skeletons/asn_system.h

@@ -75,7 +75,9 @@ typedef	unsigned int	uint32_t;
 #else	/* !defined(__vxworks) */
 
 #include <inttypes.h>	/* C99 specifies this file */
+#ifdef HAVE_NETINET_IN_H
 #include <netinet/in.h> /* for ntohl() */
+#endif
 #define	sys_ntohl(foo)	ntohl(foo)
 #endif	/* defined(__vxworks) */